Boiler feed water conditioning equipment and method



H. J. MElER March 2, 1943.

BOILER FEED WATER CONDITIONING EQUIPMENT AND METHOD Filed March 9, 1959zsheetsQsneet 1 ...mmow IHLSS 3a H. J. MEIER 2,312,570

BOILER FEED WATER CONDITIONING EQUIPMENT AND METHOD March 2, 1943.

2 Sheets-Sheetl 2 l Filed March 9, 1939 Patented Mar. 2, 1943 UNITEDSTATES` PATENT OFFICE BOLER FEED WATER CONDITIONING EQUIPMENT 'ANDMETHOD Henry J. Meier, Chicago, Ill.

Application March 9, 1939, Serial No. 260,669

19 Claims. .(Cl. 122-401) centrated boiler water of reduced suspendedcontent or devoid of suspended matter. The invention also relates toequipment for automatically carrying out the process economically,accurately and constantly at varying rates of load.

According to this invention, raw water is subjected to an ordinary hotprocess lime-soda treatment, and the thus treated water then has itsalkalinity increased by means `of recirculated boiler water so as toreduce the soluble calcium carbonate hardness to a minimum beforeaddingreagents such as phosphates, alumin-ates, tannates or the like, whichwill react with and precipitate the last traces of calcium and magnesiumhardness in the water.

The lime-soda treatment includes subjecting" the raw water to a mixtureof soda ash and lime water (calcium hydroxide). The calcium hydroxide orlime combines with excess carbon dioxide in the water and reacts withcalcium and magnesium bicarbonates to form less soluble calciumcarbonate and magnesium hydroxide. The

' soda ash is added so as to react with the calcium sulphate in thewater to form sodium sulphate and calcium carbonate.

According to this invention, the insoluble reaction products from thelime-soda treatment are settled out as sludge in a rst stage treatingtank and the lime-soda treated water with its residual hardness is thentreated with a phosphate or similar reagent in a second stage treatingtank,-

or integral compartment of the first stage tank, to'precipitate the`remaining calcium. The precipitated salts are then removed from thetreated water either by ltering it through beds of anthracite coal, by asettling process or by any other method of water clariiication.

It has been known that the hardness of the water leaving the first stageof a hot process softener decreases with an increase in excess soda ash.Likewise, an increase in caustic alkalinity beyond the point wherebicarbonates can no longer exist, and an increase in total solublesolids, in the treated'water will tend to reduce the residual calciumcarbonate hardness .to a lower point because these increases affect ythesolubility of calcium carbonate.

Since modern boiler operatingV practice demands a low carbonate andcaustic alkalinity content in theconcentrated boiler water, a minimumexcess of lime and soda ash must be used in the ordinary hot processlime-soda softening system. i

According to this invention, the water leaving the upper section of thefirst stage treatingv tank is tested by the usual chemical indicatormethods, such as phenolphthalein, methyl orange and soap, to ascertainthe hardness of the water at this stage, in order to keep proportionsand quantities of lime and soda ash being fed at the required strength.i

In order to further reduce the soluble 'calcium carbonate hardness andalso to properly-prepare this water so that only a minimum of secondarytreating chemical such as phosphates, tann'ates, aluminates, etc., willbe used, and last but not least so as to make it possible for thesecondary treating chemicals to react with thelast minute traces ofcalcium hardness, the smallest possible quantity of boiler recirculatingwater vis-introduced into the central section of the sedimentation tankby means of agcontinuous blow 'down sedimentation tank maintains adefinite but minimum caustic alkalinity in the Water issuing' from theoutlet of the softening system.

The apparatus 0f this'invention is automatic in operation and isactuated by a pressure drop lin the raw feed water as the Water passesthrough an orice. Differential proportioners are provided for feedinglime-soda solution to the rst stage treating tank, for feeding phosphatesolution to the second stage treating tank and for regulating thefeeding of recirculated boiler blown down water to either or both ofthetreating tanks or compartments. These diiferential proport'ioners caninclude diaphragm"s,lpi`stons,

Sylphon bellows andthe like connected either directly or by means ofsprings, weights or mercury columns to the chemical supply lines.

Buoyancy floats are also providedin one ofthe "chemical supply tanks toactuate a dilution .needle valve or orice adjustment and isV dischargedto an elevated ash tank from whichfit percentage of recirculation isvaried by adjustment of an orifice valve. The feed of phosphatechemicals to the second stage tank is kept at a minimum as indicated bya test for excess of phosphate existing in the water leaving thissoftening system.

at the bottoms thereof communicating with a pipe line I2. The pipe lineI2 can also communicate with additional blow-offs of other boilers of aplant (not shown on the drawings). The combined blow-down liquid orsludge from al1 of the boilers is conveyed through the pipe line I2 intoa flash tank i3 having a steam outlet I4 at the top thereof and a liquidoutlet I5 at the bottom thereof. A oat chamber l5 has a liquid inlet I1communicating with the outletl of the flash tank I3 and a steamequalizer pipe I8 at the top thereof communicating with the steam spaceof the flash tank.

It is, then, an object of this invention to prod vide a hot-processwater-softening system operable with a minimum quantity of treatingchemicals to produce water of Zero hardness if desired.

Anotherobject of the invention is to produce a lime-soda treated boilerwater free from suspended matter with a minimum of alkalinity andphosphate content.

A further object of the invention is to utilize boiler blow-down waterfor supplying part of the excess chemicals used in the water softenerreaction tanks.

A further object of the invention is to decrease the amount of boilerblow-down or discharge to the sewer in a boiler plantby use of blow downwater in a water softener.

A specific object of the invention is to provide a'hot process lime-sodaand complete phosphate treatment of boiler feed water by means ofaccurate continuous proportoners which are actuated by the raw feedwater requirements of the boiler plant.

Another specific object of this invention is to provide a simplifiedform of differential chemical proportioner which requires only onechemical pump to deliver the proportioned quantity of treating chemicalor proportioned quantity of blow down water for recirculation.

A further object of the invention is to provide a process for softeningwater wherein dilution water from either an outside source or from thesedimentation tank effectively dilutes chemical charges so that they canbe pumped by centrifugal pumps to the treating tanks or compartmentsthus to supply just enough chemicals continuously so as to carry out thedesired water softening reactions. f

`,OtherV and further objects of the invention will become apparent tothose skilled in the art from the following detailed description of theannexed sheets of drawings which disclose a preferred embodiment of theinvention.

On the drawings:

Figure 1 is a diagrammatic elevational view of of aboiler feed watersoftening apparatus accordingn to this invention.

Y Figure 2 is an enlarged, fragmentary, diagrammatic 'elevational view,with parts shown in vertical cross section, of a portion of theapparatus shown in Figure 1.

Figure 3 is an enlarged fragmentary diagrammatic elevational view, withparts shown in vertical cross section, of another portion of theapparatus shown in Figure 1.

As shown on the drawings:

In .Figure 1, the reference numerals Iii-I9 designate boiler shellshaving blow-oifs II--II `A iioat I9 is mounted in the iioat chamber andcontrols a gate valve 25 in the outlet I5 from the flash tank. The gatevalve 29 is positioned beyond the inlet l1 to the float chamber. Theoa-t I9 maintains a predetermined liquid level 2| in the flash tank.When this liquid level 2l `rises, above a predetermined point, the iioatI9 will open the valve 29 to discharge liquid into a standpipe 22. Thestandpipe 22 is vented at the top thereof by means of a vent tube 23.The bottom of the standpipe 22 has a pipe fitting 24 which is providedwith a botto-m outlet receiving a pipe line 25 and a side outletreceiving the lower end of an upwardly curved pipe line 26. A manuallyoperated'valve 25a is mounted in the pipe line 24 to act as an orificefor regulating the iiow of boiler circulating water from the standpipe.

The upper end of the pipe 26 is adapted to be i closed by a hydraulicoperated plug or'valve disc 21. The pipe 26 discharges a quantity ofboiler blow-down water into a receptacle 28 when the plug 21 is liftedoff the top of the pipe. The chamber 23 discharges boiler blow-downwater to a drain 29 communicating with a sewer (not shown). As will behereinafter described, the plug 21 is operated by differential pressureexisting in the raw water feed line. Since excess blowdown water is fedto the standpipe 22, it will always Vcontain a column of water exertingahydraulic pressure equal to the differential pressures existing in thefeed line.

Raw feed water for the boilers I0 is supplied to a feed pipe 33. in thesupply line 33 which may be either a Venturi nozzle or a removableorifice plate with a small orifice 32 therethrough. The pipe`3ll isconnected to a heat exchanger coil 33 in the lower portion of the liashtank I3 so as to minimize or obviate the iiash steam formation betweenthe valve 2! and standpipe 22. The coil 33 discharges into a pipe line34 communicating with the water coil 35 of a condenser 36 mounted on topof a sedimentation tank 31. A bypass pipe line 38 extends around thecondenser 36 and is provided with a valve 39 which is closed during thenormal operation so as to permit a maximum recovering of heat from thevented gas and air being discharged from sedimentation tank 31 throughthe vent pipe 42, condenser 35 and bleeder outlet 43 to the atmosphere.

A jet heater 46 of the customary type extends through the top of thesedimentation tank 31 and is mounted on the manhole plate 4I which is inthe top of the tank. The jet heater receives the water from thecondenser coil 35 or from the bypass pipe line 33.1 The water suppliedto the jet heater 4B is sprayed into the tank 31 through a spray head 44located at the lower end of the heater in the top portion of the tank.

The steam outlet I4 from the flash tank I3 receives a pipe line 45communicating with the steam-inlet 46 to the top of the tank 31. Addi- Arestriction 3| is mounted tional steam to heat the' incoming raw wateris supplied to the inlet 46 through a steam pipe 41 which may beconnected with a source of eX- haust steam from prime movers orauxiliaries of the boiler plant.

The raw feed water from the pipe 39 is thus heated by the hot blow-downliquid in the flash tank I3, by steam and hot air passing from the tank31 into the condenser 36 before it is sprayed into the steam in the topof the tank 31. A constant liquid level 49 of water is maintained in thetank 31 by a float 50 which controls a valve I in the pipe line 34. Whenthe float 50 rises the valve 5| is closed to shut off the water supplyto the spray 44. 2. f

The tank 31 has a hopper bottom 52 for the collection of sludge or otherprecipitated solids in the tank. The collected or settled sludge is thenperiodically drained from the bottom of the hopper 52 through a drainline 53 equipped with l a hand-operated valve 54. The drainage 'from theline 53 can be dumped into a sewer drain 55.

The sedimentation tank 31 has an inverted cone member 55 mounted thereinon legs and braces 51 which hold the mouth of the cone in spacedrelation from the bottom and from the side walls of the tank. The apexof the cone receives an outlet pipe 58 extending through the side wallof the tank 31 and into a phosphate reaction tank 59. The pipe 58receives an upturned leg 89 in the center of the tank 59. The leg 68terminates in a spaced relation from the top of the tank 59 at a levelbelow the liquid level The discharge side 58 of the pump E1 cancommunicate with the boilers i9 to supply softened boiler water thereto.

The heated feed water sprayed into the sedimentation tank 31 is treatedwith a lime-soda solution fed to the tank by a prcportioning device tobe hereinafter described. The reaction products precipitated from thewater in the tank 31 can settle to the bottom of the tank. The treatedwater, however, ows into the mouth of the cone 56 and is discharged fromthe apex of the cone through the pipe 58 into the phosphate tank 59where it is further treated to reduce thei' soluble calcium carbonatehardness thereof, and to precipitate additional salts remaining in thewater. The phosphate treating solution is supplied to the tank 59 bymeans of a proportioning device which will be hereinafter described. The

phosphate-treated water is then filtered through the filter bed 64 andsupplied to the boiler by the boiler feed pump 61.

As best shown `in Figures 1 and 2,4 the limesoda solution for thesedimentation tank 31 is'ji prepared in a tank 19 equipped with anagitator 1| driven by a motor 12. The solution in the tank 19 is drainedtherefrom through a pipe line 13 communicating with the bottom of thetank.

The pipe line 13 has a manuallyoperated valve 14 therein and is joinedto a T 15. One branch of the T 15 receives a pipe lineA 16 havingamanually-operated valve 11 therein. `The pipe 18 can be connected withother tanks .ifdesired or may be used as a dump forthe .tank 18. '."I'heother'branch of the T 15 receives a pipe line 18 having amanually-operated valve 19 therein. A regulating orifice valve is alsoprovided yin the pipe line 18. The regulating orifice valve 89 isautomatically controlled as will hereinafter be described.

The pipe line 18 communicates with a dilutionwater feedline 8| connectedto a centrifugal pump 82. The discharge side of the pump 82 receives apipe line 83 having a valve 84 therein. The pipe line 83 enters thesedimentation tank 31 and receives a spray head 85 on the end thereof.The spray head 85 is positioned under the heater spray head 44 at alevel in the tank 31 abovethe liquid level 49. The centrifugal pump '82thereby supplies a lime-soda solution to the Vtank 31 in spray form.

For obvious reasons, the pumping capacity of centrifugal pumpv 82 willbe larger than necessary,hence the valve 84 is throttled but'alwaysallowspassage of the maximum amount of proportioned chemical that may bedemanded by the system. Obviously, during lightload periods a greaterquantity of dilution water must be added to the proportioned chemical inorder to satisfy the throttled capacity of the centrifugal pump 82.

' A float tank 88 is mounted alongside of the lime-soda tank 10 and hasthe bottom thereof somewhat lo-wer than the bottom of the tank 10.

The float tank 88 receives a pipe line 81 through the bottom thereof.The pipe line 81 is connected to the dilution-water feed line 8| andalso to a pipe line 88. The pipe line 88 receives a -tting 89 on the endthereof. One connection V of the fitting 89 receives the pipe line 25from the blow-down water standpipe 22. A third connection of the fitting89 is joined With the inlet of a pump 99. The pump 98 discharges through1B and 86 on a pivotal support 94. One end of the beam suspends abuoyancy float in the rvtank 10, while the other end of the beamsusrvpends a bucyance float 96 in the tank 86. The

buoyancy float 96 is suspended at a lower level than the buoyancy float95 so that the liquid level 91 in the tank 18 will be from twelve totwenty-four inches higher than the liquid level '98 in the tank 85, aswill be hereinafter described.

The beamV 93,- from which the float 96 is suspended; carries anextension member 99 receiving'a link rod Y|58 on the end thereof. Thelink lrod llililis connected to one end of a'centrally pivoted lever armlill. The other end ofthe ,'lever'arm li!! operates the control rod |82of a regulating orifice valve |93 in the dilution-water feed line 8|.The valve '|93 is positioned ahead of the pipe line 81 to the float tank85 So'that water will be supplied to the tank 86 when the liquid level98 falls more than a predetermined amount below the liquid level 91 inthe tank 19. The buoyancy floats 95 and 9B operating the dilution watervalve |83 only open the valve when the liquid level 98 falls more than apredetermined distance below the level of the lime-soda solution 91. Thefloats promptly close the valve when the desired difference in levels isreached. Since the liquid level 91 is always above the liquid level 98,the dilution water will not enter the rpipe line 18 even if the valve 88therein is open.

The plug or valve disc 21 for the blow-off water standpipe 22 and thevalve 88 in thelime-soda pipe line 'I8 are automatically controlled bythe drop in pressure caused by the flow of the raw water in the feedline 38 as it passes through the oriiice 32 whenever the float 5e opensthe valve For this purpose, a pipe line IM communicates with the feedwater line 3|) at a point ahead of the orifice 32 therein. A second pipeline |05 communicates with the feed pipe 30 at a point beyond theorifice 32. A branch H36 of the pipe line me communicates with the highpressure side of a piston chamber III'I having a piston |08 v slidabletherein and connected through a piston rod ISS to the plug or valve disc2.

A branch I It of the pipe line |05 communicates with the low pressureside of the piston chamber IEE'I beneath the piston |88 therein. Asecond branch of the pipe line |04 communicates with the high pressureside or top of a piston chamber l2 having a slidable piston I |3therein. The piston |I3 has a piston rod II 4 connected to a centralportion of a pivoted lever arm H5.

`the low pressure side of the piston chamber H2 beneath the piston I I3therein.

VIn operation, raw water is supplied tothe tank 31 whenever the liquidlevel 49 falls to cause the iioat to open the valve 5I in the raw waterline 30. When no feed water is removed from the system by the boilerfeed water pump Si', the valve 5| is closed, no water flows through thepipe 39, and the pressure on both sides of the:V Y'orifice 32 `isequalized. Under these conditions,

however, the pumps S2 and 99 are still operating and are supplied withdilution water so that they will always have a positive pressure attheir Y inlets determined by the level 98 in the float tank 88. Abecause the head pressure of water in the standpipe will be sufficientto overcome the weight of The plug valve 21 will then be Wide open,

the piston |33. Blow-off water Will then` drain to the sewer through thedrain 29, and there will be practically no flow of boiler circulatingwater through the orifice valve 25a because there is practically no headpressure in the standpipe 22.

Under the same equalized pressure conditions,

the spring I I'i will hold the valve Bil closed so that no chemicalsolution will be removed fromv the tank 1|).

- When the' raw feed water is not owing into the system, the boilerblow-down automatically goes to the sewer and no chemical is supplied tothe sedimentation tank. However, when the boiler feed Vpump 6i' isoperated to Vwithdraw water Vfrom the system, the liquid level 49 willfall and the valve 5| will open, thereby causing a raw Water iiow and adifferential pressure through the orifice 32. will then operate inaccordance with the pressure differential between the two sides of theoriiice. The piston I will operate the valve Sil to supply aproportioned quantity of lime-soda solution to the pump 82.

- The piston IGS will operate the plug valve 21 to thus'build up a headpressure in the standpipe 22 until it is equal to the differentialpressure,

and thus the proportioned boiler circulating wa# The pistons |98 and|'|3V ter will be supplied to the pump 9B. The oriiice valve 25acontrolling the iiowof blow-oil water into the pump Si! is throttleddownso that the inleu of the pump 98 will receive both blow-down waterand dilution water from the iloat chamber 36 or the supply line 8|, asdetermined by chemical tests on samples of water drawn from the going tothe sedimentation tank. Y ChemicalsV available in the blow-down waterAare utilized by supplying a proper quantity of boiler circulating waterdirectly to the sedimentation tank.

The phosphate reaction tank is likewise automatically supplied withphosphate in accordance with the requirements of the water beingtreated. For this purpose, a phosphate tank |39 is provided for thepreparation and storage of phosphate solution, such as an aqueoussolution of mono-sodium phosphate. The tank is drained through a drainline |3| having a manually operated gate valve |32 therein. Thepipe line|33 receives a T fitting |33, as best shown in Figure 3. One branch 0fthe T tting receives a pipe |313 having a valve 35 therein permittingconnection of the drain |32 with another phosphate tank drain line, ifdesired, or permitting the inlet of a bump |33.

an emptying of the tank |39. The other branch of the T |33 receives apipe line |35 having a manually-operated valve |3611 adjacent the T. Thepipe line |35 communicates with the dilution-water supply line SI andthe drain line 81 from the iioat chamber 85. The pipe line |36 in turnis connected through a branch pipe |31 to The discharge end of the pump|33 is connected through a pipe line |39 to the top of the phosphatetank 58. A manually operated valve |40 is provided in the pipe lineV|39, in order to throttle the pump capacity as desired.

A regulating oriiice valve Intl is mounted in the pipe line |35 betweenthe connection with the pipe 8i and the manually-operated valve |36a.The regulating orifice valve IdI has an operating rod I connected to theend of a pivotedlever arm m3; The other-end of the lever arm" |43 isconnected to a link rod Hit. rIhe link rod |44 is operated by a lSylphonbellows I' mounted in a housing hifi. The bellows |135 has an operatingYrod It? extending through the housingand conber Ii. A glass column |52extends upwardly -V from the mercury chamber i5! and communicates with aclosed chamber |53, at its bottom. Asthe Sylphon bellows is collapsed,the fluid therein is forced into the mercury chamber 35|,

thus causing the mercury to rise in the column |52. If desired, a linearscale (not shown) can be pissed behind the glass column |52 so thatevery inch of mercury in the column will designate one foot ofdiiferential pressure through the orifice 52. The chamber |53 receives apiped line |54 communicating with the pipe |05.

The housing |45 for the bellows |45 has a pipe line |55 extendingtherefrom and connected to the pipe which, in turn, communicates withthe pipe |55.

ply line is equal. However, when water is drawn through the system bythe feed pump 61, the diierential pressure of the orice 32 will causeSylphon bellows |45 to collapse until the displaced uid therein hascaused the mercury column pressure to equal the raw water differential'pressure, to thus open the valve in accordance with the pressure drop orflow of raw water y through the orice. The pump |38 will then rey ceivephosphate solution from the tank |30 andv will supply the same to thephosphate tank 59.

I'he inlet side of the pump |38 is maintained under a constant pressurethrough the buoyancyV oats described in connection with the tank 15,

since this pump also receives dilution water from the supply line 8|.The strength of the phosphate solution in the tank |35 is changed inaccordance with the excess of chemical in samples taken from a samplingtube |55 communicating- With the drain line from the filter tank 55.

If desired, the blow-off water can be supplied to the phosphate tankinstead of to the sedimentation tank, by connecting the pipe and oricevvalve 25a to the inlet of the pump |38 instead of to the inlet of thepump 56. Alternatively, the blow-olf Water can be fed to both thesedimentation and the phosphate tank by also connecting the pipe line 25with the inlet to the pump |33. plied to either the pump 95 or the pump|38 can oe controlled by regulation of the valve 25a in accordance withthe caustic alkali strength of samples taken from the sampling tubes |51orl |58 and |56.

Obviously, piston or diaphragm operated valves could be used in place ofthe Sylphon bellows arrangement for control of the phosphate feed to thetank 59.

From the above description, it should be understood that availablechemicals in the blowdown water are utilized for the water-softeningprocess; that the amounts of new chemicals supplied to the sedimentationtank and to the phosl phate tank are automatically regulated by demandsof the system as determined by a pressure drop in the raw water supplyline; that dilution water is supplied to the chemicals for.,

maintaining a constant pressure drop across the regulating orificeValves and for maintaining a constant pressure at the pump inlet; andthat the system is therefore entirely automatic.

It will, of course, be understood that various details of the inventionmay be varied through The .amount of blow-0E water sup-A the reagentsolution conduit, a raw water feed conduit for supplying water to thetank, means l responsive to Water flow through the raw water feedconduit for actuating the Valve in thereagent conduit, and meanscontrolling the valve in the dilution water conduit for maintaining aconstant pressure drop betweenl the reagent solution conduit and thedilution water conduit.

2." Water conditioning apparatus comprising a water treating tank, a rawwater supply convduit for said treating tank, a reagent supply tank, adilution water supply tank, a dilution water supply conduit for saidlast tank, a dilution Water valve in said dilution water supply conduit,a pump for supplying reagent to the treating tank, a conduit connectingthe reagent l ltank with the pump inlet, a reagent valve in l saidconduit, a conduit connecting the dilution Water tank with the pumpinlet, balanced buoyancy oats in said reagent tank and said dilutionwater tank for actuating the dilution water valve to supply water to thedilution water tank for maintaining a positive pressure at the pump finlet, means creating pressure differentials'irl the raw Water supplyconduit, pressure-res'pn-. sive means actuated by said pressurediiertials for operating the reagent valve to control the feeding ofreagent to the pump, and conv necting means between said raw watersupply i yconduit and said pressure responsive means for L downliquidfrom a boiler to said iiash tank,'a standpipe receiving blow-down liquidfrom said y flash tank, a water softening tank, a pump for' supplyingliquid from the standpipe to the waterY softening tank, a raw watersupply conduit for', the Water softening tank, flow restriction means4in said Water supply conduit for creating 'presi-f sure differentialstherein, means sensitive to said pressure diiferentials for dischargingblow-down., water from the standpipe, and connecting means between saidwater supply conduit and/said1` last means for transmitting saidpressure differentials therebetween.

4. In water conditioning apparatus for boilers, the combination with aconduitfor .receiving blow-01T liquid from a boiler, of a ash tank'receiving the blow-01T liquid, a Water-softening tank, ra pipe joiningthe vupper portion of tli' ash tank with the water softening tankto4supply steam to said water softening tank, L a standpipe receivingliquid from the flash tank, a raw Water supply conduit for 'the watersoftening tank, a coil in said raw water.l supply conduit extending intosaid iiash tank' in heat exchange relation with the liquid in the ilashtank, and means for supplying blow-olify water from the standpipe to thewater softening tank for utilization of chemicals contained in theblow-loft' Water.

5. AAhot process water softening, apparatus,- comprising a sedimentationtank, a phosphatereaction tank, means for supplying raw water to thesedimentation tank, means vfor supplyingv treated water from thesedimentation :ank to` the phosphate tank, a lime-soda supply conduitfor the sedimentation tank, means for supplyingI a lime-soda ash reagentthrough said Supply conduit, a phosphate supply conduitvfor thephosphate reaction tank, means for supplying a. phosphate reagentthrough said lastsu'pply ioni-jA duit, valves in said lime-soda andphosphate` conduits, --means creating pressure differentials inthe raw.water supplying means, and pressure responsive means controlled by saidmeans creating pressure differentials and connected to the valves insaid conduits for operating the valves to supply just sufficient reagentto the tanks for effecting a desired softening of the raw water.

6; Water softening apparatus for boilers having a continuous blow-downWhich comprises a sedimentation tank, a plurality of dilution waterconduits communicating with said sedimentation tank at different levelstherein, a blow-down water conduit receiving blow-down liquid from theboiler and communicatingrwith one of said dilution water conduits, areagent supply conf duit'communicating with another of said dilutionwater conduits, a valve in said reagent supply conduit, a dischargeValve in said blow-down water conduit, a raw water conduit communieatingwith said tank, means inV said raw water conduit for creating pressuredifferentials therein, pressure sensitive means operating said valves tocontrol the amount of reagent supplied' to the tank andthe discharge ofblow-down water and conduits joining the raw water-conduit and thevpressure sensitive means.

7. Boiler feed water conditioning equipment for boilers havingcontinuous blow-down orifices which comprises a lime-soda sedimentationtank, a phosphate reaction tank, a blow-down water standpipe receivingblow-down liquid from the boiler, a first dilution Water conduitcommunieating with the sedimentation tank below the top thereof, aseco-nd'dilution water conduit cornmunicating with the sedimentationtank near the top thereof, a third dilution water conduit communicatingwith the top of the phosphate reaction tank, means connecting thestandpipe with the first dilution water conduit', a discharge valve forsaid standpipe, a lime-soda supply conduit communicating with the seconddilution water conduit, means for supplying a lime-soda ash reagent tosaid conduit, a valve in said limesoda' supply conduit, a phosphatesolution supply conduit communicating with the third dilution waterconduit, means for supplying a phosphate reagentto said conduit, a valvein said phosphate solution supply conduit, a raw feedV waterconduitjcommunicating with the top of the sedimentation tank, means insaid raw water conduit for creating pressure differentials therein, andpressure transmission means connecting said raw, water conduit and allof said valves for` actuating said valves to control blow-down dischargeand lime-soda solution and phosphate solution f eed into the dilutionwater conduits according to the amount of raw feed water supplied to thesedimentation tank.

l 8. Water softening apparatus for boilers havingfa continuous blow-downwhich comprises a settling tank, means for feeding raw water to saidtank, means for spraying raw feed water into the top of the tank, meansfor spraying chemical reagent into the top of the tank, means forfeeding blow-down water into the central portion of the tank, means insaid raw water feeding means for creating pressure differentialstherein,means for varying the chemical reagent and blow-down water feedto the tank, and pressure transmission means connecting said raw Waterfeeding meansand said varying feed means for controlling the chemicalreagent and blowd own water feed in accordance with variations in theraw water feed.

` 9. The process of reducing the'hardness of water which comprisescontinually feeding Vdilution Water to a settling tank, feeding rawwater to they tank in accordance with demands for treated water, feedinglime-soda ash solution to the dilution water, controlling the amount oflime-soda ash feed with the raw water feed,`

heating the ingredients in the tank, settling out .precipitated matter`from the liquids in the tank,

withdrawing clarified liquid from the tank into a phosphate reactiontank, continually supplying dilution water to the phosphate reactiontank, feeding phosphate solution toV the dilution- Water andcontrollingv the phosphate solution feed with the raw water feed to thesettling tank.

10. The process of conditioning boiler feed water for a boiler plantwhich comprises spraying raw water into the top of a settling tank inaccordance with the demands of the boiler, continually sprayingcontrolled lquantities of dilution water into the top of theV tank forcommingling with the raw water spray, feeding limesoda ash solution intothe dilution water spray, and proportioning ,the amount of lime-soda ashsolution in accordance with'the amount of raw water spray.

l1. The process Vof conditioning boiler feedA water for a boiler plantwhich comprises spraying raw feed water into `the top of a settlingtank, spraying dilution water into the top-of said tank beneath the rawWater spray, admixing lime-soda ash solution ywith the dilution Water,proportioning the lime-soda ash solutionV in accordance with the rawwater spray, feeding additional dilution water to the tank below theliquid level thereof, admixing boiler blow-down Water with saidlast-mentioned dilution water, allowing precipitated matter to settle tothe bottom of the tank, drawing off clarifiedV liquid from the tank intoa phosphate reaction tank, continually supplying dilution water to thephosphate reaction tank, proportioning phosphate solution with saidlast-mentioned dilution water in accordance with the amount of raw`water sprayed into the settling tank, and filtering the water treatedin the phosphate reaction tank.

12. The process of conditioning boiler feed water which comprisescontinually blowing down a boiler, flashing steam from the blow-downwater, collecting the blow-down water, heating make-up water with heatfrom the blow-down Water and flashed steam,` supplying the heatedmake-up water to a treating tank, supplying water-treating chemicals tosaid tank, supplying collected blow-down water to said tank,automatically controlling the chemical feed yand blow-down water feed tosaid tank in accord-A ance with the make-up water to the tank-,andautomatically discharging excess collected blowdown Water to waste. r

13. The method of conditioning boiler Vfeed Water which comprisessupplying make-upwater to a treating tank, supplyingH water-treatingchemicals to said tank at different levels in the tank, admiXing boilerblow-downwater with the chemicals supplied to the lowerV level ofthetank, discharging excessive boiler blow-down water, and automaticallycontrolling chemical feed and the blow-down water feed'to thetahk inaccordance with the make-upwater supplied toV the tank. e v 14. Theprocess of conditioning boiler vwater which comprises feedingproportioned quantities ofA raw water, Water softening chemicals and ingtreated water from the settling tank to a phosphate reaction tank,feeding phosphate water treating solution to said reaction tank, andcontrolling the amount of boiler blow-down water feed to the settlingtank in accordance with the caustic alkalinity of the treated waterdischarged from the phosphate tank.

15. In water conditioning equipment a tank for reagent solution, a drainline for said tank, a valve in said drain line, a bellows, meansconnecting said bellows and said Valve for co-movement, a housing forsaid bellows, a water conduit, an orifice plate in said water conduit, atube connecting the conduit on the inlet side of the orifice with saidhousing, a mercury column communicating with the interior of thebellows, and a second tube joining the opposite end of the mercurycolumn with said conduit on the outlet side of the orifice wherebypressure differentials on opposite sides of the orifice will effectmovement of the bellows to open and close said Valve and controldischarge of reagent from the tank through said drain line.

16. In water conditioning equipment, a reagent tank, a drain line forsaid tank, a drain valve in said drain line, a dilution water conduitcommunicating with said valve, a control Valve in said dilution waterconduit, means operating said control valve to maintain a constantpressure drop between the drain line and the dilution water conduit, afeed water conduit, means creating pressure differentials in said feedwater conduit, a'reaction tank for receiving said dilution water, feedwater, and reagent from said drain line, and pressure sensitive meanscontrolled by said created pressure differentials for operating saiddrain valve whereby the reagent draining from said reagent tank to saidreaction tank will be controlled only by the pressure differentials inthe raw water feed conduit and will be independent of the level of thereagent in the reagent tank.

17. The process of conditioning boiler water which comprises feedingproportioned quantities of raw water, water softening chemicals andblow-down boiler water to a settling tank, reacting the water in thetank with said chemicals and controlling the amount of boiler blow-downwater feed to the tank inversely with respect to the degree of causticalkalinity of the treated water discharged from the tank.

18. The process of conditioning boiler water which comprises feedingproportioned quantities of raw water, water softening chemicals andblow-down boiler water to a settling tank, reacting treated water fromthe settling tank with a phosphate treating solution, and controllingthe amount of boiler blow-down water feed to the settling tank inverselywith respect to the degree of caustic alkalinity of the phosphatetreated water.

19. Water softening apparatus which comprises a sedimentation tank, adilution water conduit communicating with the tank, a raw water feedconduit communicating with the tank, a lime-soda solution conduitcommunicating with the dilution water conduit, means for supplying alime-soda reagent through said limesoda solution conduit, a valve insaid lime-soda solution conduit, a phosphate reaction tank, meansjoining the sedimentation tank with the phosphate reaction tank tosupply water from the sedimentation tank to the phosphate reaction tank,a dilution water conduit communicating with said phosphate reactiontank, a phosphate supply conduit communicating with said last mentioneddilution water conduit, means for supplying a phosphate reagent throughsaid last mentioned dilution water conduit, a Valve in said phosphatesolution supply conduit, means in the raw water feed conduit forcreating pre'ssure differentials therein, and means in communicationwith the raw water feed conduit controlled by said pressuredifferentials for operating both valves to vary the amount of lime-sodasolution fed to the sedimentation tank and the amount of phosphatesolution fed to the phosphate reaction tank in accordance with theamount of raw feed water fed to the sedimentation tank.

HENRY J. MEIER.

